Corneal Surgeries Overview

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Questions and Answers

What is one of the key outcomes of using amniotic membrane grafts after 3 months?

Excellent integration and cosmetic appearance (correct)

Weak integration with surrounding tissue

Poor cosmetic appearance

Presence of significant scarring

In which field is human amniotic membrane transplantation primarily utilized?

Cardiology

Ophthalmology (correct)

Dermatology

Orthopedics

Which of the following statements best describes the publication source of the information?

A pamphlet on tissue engineering.

A thesis on human biology.

An online encyclopedia of medical procedures.

A medical journal focused on transplantation. (correct)

What is the document's citation format for the authors Malhotra and Jain?

Last name, First initial. Title. Journal name year; volume(issue): page numbers. Signup and view all the answers

What was the primary research focus of Malhotra and Jain in their publication?

Different modalities of its use in ophthalmology. Signup and view all the answers

What was the evidence of effectiveness noted in the study regarding amniotic membrane grafts?

High rates of integration with minimal complications. Signup and view all the answers

Which of the following is NOT mentioned as an outcome of the amniotic membrane graft at 3 months?

Inflammatory response. Signup and view all the answers

What kind of photographs were used in the study concerning amniotic membrane grafts?

Serial photographs. Signup and view all the answers

What is the primary function of antimicrobial peptides (AMPs) during corneal wound healing?

To protect against infection Signup and view all the answers

During which phase of corneal wound healing do epithelial cells begin to adhere to the basement membrane (BM)?

Migration phase Signup and view all the answers

What is a significant outcome of severe chronic inflammation in the cornea?

Excess of fibroblasts and disorganized collagen Signup and view all the answers

Which growth factor is not commonly associated with promoting epithelization in corneal treatments?

Neutrophil-activating peptide (NAP) Signup and view all the answers

How does amniotic membrane treatment aid in corneal wound healing?

Prevents epithelial apoptosis Signup and view all the answers

Which condition is specifically mentioned as a potential use case for amniotic membrane treatment?

Exposure keratitis Signup and view all the answers

In which phase of corneal wound healing does apoptosis of keratinocytes primarily occur?

Latent phase Signup and view all the answers

What role does the amniotic membrane play in the healing process of corneal epithelial defects?

It minimizes inflammation and neovascularization Signup and view all the answers

What is the primary cellular source for the basal cell proliferation during the corneal wound healing process?

Columnar epithelial cells Signup and view all the answers

What is a major characteristic of amniotic membrane treatment in corneal conditions?

It provides a thick basement membrane for support Signup and view all the answers

Study Notes

Corneal Wound Healing Phases

Healing involves four distinct phases: latent, migration, proliferation, and attachment.

Latent Phase (First 6 hours)

Reduction of intracellular junctions and hemidesmosomes, promoting the removal of damaged basal cells.
Infiltration of neutrophils occurs, along with keratinocyte apoptosis.

Migration Phase (6-36 hours post-injury)

Epithelial cells begin migrating to close the surface gap.
Cells start adhering to the basement membrane (BM) with primary neutrophil wave at 18 hours and secondary wave at 30 hours.
Neutrophils contain antimicrobial proteins (AMPs) for protection.

Proliferation Phase (36-48 hours)

Basal cells from the columnar layer proliferate, differentiating into wing and superficial cells.

Attachment Phase (48 hours)

Epithelial cells adhere firmly to the BM, increasing intercellular junctions to prevent separation and restore normal functionality.

Importance of Antimicrobial Peptides (AMPs)

Present throughout the wound healing process including tear film.
CAP37 protein plays a key role in antimicrobial defense.

Corneal Scarring

Severe chronic inflammation, marked by lymphocyte and neutrophil infiltration, leads to fibroblast proliferation and disorganized collagen, resulting in scarring.
Corneal scarring can lead to low visual acuity (VA).

Amniotic Membrane in Corneal Treatment

Utilized for corneal ulcers, pterygium, and epithelial damage, promotes corneal regeneration without causing neovascularization.
Composed of thick basement membrane (BM) derived from placenta, rich in collagen and proteins aiding in keratinocyte proliferation.

Growth Factors in Amniotic Membrane

Contains signaling molecules such as epidermal growth factor (EGF), transforming growth factor beta (TGFβ), fibroblast growth factor (FGF), and platelet-derived growth factor (PDGF) which promote epithelialization.

Benefits of Amniotic Membrane

Facilitates quicker epithelial healing and reinforces adhesion while preventing apoptosis and reducing pain.
FDA-approved PROKERA is a cryopreserved amniotic membrane product.

Clinical Applications of Amniotic Membrane

Used in treating conditions like exposure keratitis, neurotrophic corneal diseases, bullous keratopathy, persistent corneal epithelial defects, recurrent corneal erosion (RCE), Stevens-Johnson Syndrome (SJS), acute corneal burns, and others.

Coverage and Integration

Amniotic membrane can completely cover the cornea and allows cell migration from the limbus, promoting healing.
Successful integration noted in procedures such as covering bare sclera post-pterygium excision with excellent cosmetic results observed after three months.

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Description

Explore the intricate phases of corneal wound healing, focusing on the regeneration of the epithelium. This quiz covers the latent and migration phases, detailing the cellular responses involved during these crucial stages of healing.